LAUSR

Constructing high strength pH sensitive supramolecular polymer hydrogel remains very challenging due to the unavoidable network swelling caused by ionization of acid or basic groups at a specified pH. In this work, we proposed a simple and very convenient approach to fabricate high strength pH responsive supramolecular polymer (SP) hydrogels by one-pot copolymerization of N-acryloyl glycinamide (NAGA) and 2-vinyl-4,6-diamino-1,3,5-triazine (VDT), two feature hydrogen bonding monomers. In these PNAGA-PVDT SP hydrogels obtained, the hydrogen bonding of NAGA was shown to play a dominant role in reinforcing strength, while the hydrogen bonding of diaminotriazine served as a pH sensitive moiety. At pH 3, the mechanical properties of PNAGA-PVDT hydrogels decreased to a different extent due to the breakup of hydrogen bonding; in contrast, the hydrogel resumed the original strength while pH was raised to 7.4 because of reconstruction of hydrogen bonding. Over the selected pH range, the PNAGA-PVDT hydrogels exhibited up to 1.25 MPa tensile strength, 845% breaking strain, 69 kPa Young’s modulus and 21 MPa compressive strength. This novel high strength pH-responsive SP hydrogels may find applications in biomedical and industrial fields.